The empirical study of gradation of crushed sand concrete properties using six sigma DMAIC methodology

Abstract

Fine aggregate plays a key role as a filler material in concrete’s fresh and hardened properties. Generally, in Portland cement concrete aggregate occupies 70-85% by weight and 60-70% by mass. In Pakistan, Lawrence pur the sand as the only sand that meets the ASTM standards. But due to heavy transportation costs, it is not cost-effective to use in most parts of the country. The tests were carried out in accordance with ASTM standards, and the concrete mix designed with three water-cement ratios of 0.40,0.45, and 0.50 called for a mixing procedure. At 28 days of curing, an M30 concrete mix comprising five control mixes including parent concrete was evaluated and compared to parent concrete. This experimental work aimed to enhance the fresh and hardened properties of concrete such as the workability of concrete mix, compressive, and flexural strengths by using locally available Jhelum River sand gradation crushed sand (passing sieve #4, the waste product of Sargodha coarse aggregate), s a fine aggregate material. Using six sigma DMAIC Methodology 9 defects in the Jhelum River sand and control mix have been identified and corrective measures were taken to improve the quality of the concrete mix. The results derived from this experimental work show that adding 50% crushed sand in Jhelum River sand increases compressive strength by 27% and flexural strength by 20% which makes it according to ASTM Standards. The use of crushed sand as an alternative to natural river sand efficient and safe material. This control mix also reduces the construction cost by 10% in comparison to lawerancepur sand.